Secondary Battery Terminal Plate Short-Circuit Prevention
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Solution Overview
Problem
Secondary batteries face challenges in ensuring secure electrical connections and pressure relief mechanisms to prevent short circuits and ensure safe operation, particularly as internal pressure increases.
Innovation Solution
The design incorporates a cap assembly with a short-circuit hole and a deformable short-circuit member that contacts the terminal plate when internal pressure exceeds a certain value, along with a coupling terminal system that includes a terminal plate with a lip and a protrusion part for secure electrical connections, using materials like aluminum and copper alloys for enhanced durability and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a terminal plate with holes is used to connect coupling terminals, then electrical connections are established, but short circuits may occur between positive and negative terminals
Solution Approach 1:
An insulation member is introduced as an intermediary between the terminal plate and the short-circuit member. This insulation member includes through holes that allow the short-circuit member to contact the coupling terminal while preventing direct electrical contact between the short-circuit member and the terminal plate, thus avoiding short circuits while maintaining the pressure relief function
Solution Approach 2:
The connection structure is segmented into multiple functional components: the terminal plate for electrical connection, the insulation member for electrical isolation, and the short-circuit member for pressure relief. This segmentation allows each component to perform its specific function without interfering with others, particularly preventing short circuits while maintaining electrical connectivity
2Reliability
If internal pressure increases in the battery, then safety risks arise, but adding pressure relief mechanisms may compromise structural integrity
Solution Approach 1:
The short-circuit member is designed to automatically activate when internal pressure increases. It deforms under pressure to contact the coupling terminal through the insulation member, creating a short circuit that triggers safety mechanisms. This self-service mechanism provides pressure relief without requiring external intervention or compromising structural integrity
Solution Approach 2:
The harmful effect of increased internal pressure is converted into a beneficial safety mechanism. When pressure rises, it causes the short-circuit member to deform and contact the coupling terminal, creating a controlled short circuit that prevents more severe damage. The harmful pressure increase thus triggers a protective response
3Reliability
If aluminum or aluminum alloy is used for the terminal plate, then electrical conductivity and durability are improved, but weight increases
Solution Approach 1:
The material composition of the terminal plate is optimized by using aluminum or aluminum alloy with specific properties. This parameter change provides improved electrical conductivity and durability while keeping the weight relatively low compared to other conductive materials, achieving a balance between performance and weight
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances the safety and reliability of secondary batteries by preventing short circuits and ensuring secure electrical connections, reducing electrical resistance, and allowing for secure coupling with bus bars, thereby improving overall battery performance and safety.
Implementation Method 1
The short-circuit member may be a deformable plate including: an edge part fixed to the cap plate; and a round part extending from the edge part and including a convex side facing an interior of the secondary battery. The round part may be configured to deform and contact the bottom side of the terminal plate when an internal pressure of the secondary battery increases to a predetermined value or higher.
Implementation Method 2
The protrusion part and the collecting part may be connected to each other by friction welding.
Data Source
AI summary
Provided is a secondary battery including an electrode assembly, a case accommodating the electrode assembly, a cap assembly, and an electrode terminal electrically connected to the electrode assembly. The cap assembly includes a cap plate disposed over an upper opening of the case. The electrode terminal protrudes outwardly from a terminal hole of the cap plate. The electrode terminal includes a collecting terminal extending through the terminal hole of the cap plate, a terminal plate coupled with the collecting terminal, and a coupling terminal coupled with the terminal plate. The cap plate includes a short-circuit hole therein. The short-circuit hole is at a position corresponding to a position of the coupling terminal. A short-circuit member covers the short-circuit hole.